Device and method for securing, including earthquake resistant securing of equipment cabinets

ABSTRACT

The invention relates to securing devices, including securing devices for earthquake-resistant securing of an equipment cabinet, which is adapted to accommodate electronic/electric equipment, onto a concrete floor ( 6 ). The securing device comprises an assembly plate ( 1 ) and at least one spacer plate ( 2 ) adapted to bear against the concrete floor for positioning of the assembly plate a distance above the concrete floor. The assembly plate and the spacer plates include common through holes for securing the assembly plate and the spacer plates to the concrete floor by anchor bolts ( 7 ), as well as common threaded holes ( 5 ) for securing of the cabinet onto the securing device by securing bolts ( 13 ). The invention also relates to a method for earthquake-resistant securing of an equipment cabinet.

FIELD OF THE INVENTION

The present invention relates generally to securing devices and, moreparticularly to securing devices including securing devices forequipment, equipment cabinets and earthquake-resistant securing.

BACKGROUND OF THE INVENTION

When constructing installation plants for e.g. telephony,telecommunication or electricity networks, it is common practice toarrange the equipment in cabinets for sake of e.g. space-saving and easyaccess during installation. The cabinets can be of the closed type,having wall elements essentially on all sides, or of the open rack type.

When building up plants of that kind in earthquake zones, it isdesirable to mount the cabinets to the floor or support structure in anearthquake safe way, such that the cabinets do not fall or becomedisplaced during an earthquake, since it is important that this kind ofinfrastructure installations will be maintained and still function evenafter the earthquake.

In cases where the support structure is a concrete slab or a concretefloor structure, it has been common, according to prior art, to securethe cabinets directly into the concrete by means of anchor bolts, e.g.expander bolts or chemical binding anchor bolts. Normally one bolt ineach corner of the cabinet.

There are essentially two main types of equipment cabinets in use today,which require somewhat different ways of securing the cabinets to thesupport structure. In one embodiment the cabinet is provided withnormally four stem feet, i.e. supporting feet each having a stem orshaft part and a foot part, which bear against the concrete floor andwhich has a larger cross sectional measure than the stem. When securingcabinets equipped with stem feet, it is common practice to use aclamping beam having a fork formation in each end, more exactly eachcomprising two fork arms and an intermediate slot in the longitudinaldirection of the clamping beam. During mounting the clamping beam ispositioned between pairs of stem feet, such that at least two clampingbeams are required to secure each cabinet. The clamping beams aresecured by anchor bolts to the concrete floor and the length of eachclamping beam is telescopic variable. In this way the fork formation ineach end of the clamping beam can be moved towards the respective stemfoot and engage the stem foot, such that the fork arms bear against theupper side of the foot part on each side of the stem, which accordinglyis positioned in the slot of the fork formation. When tightening theanchor bolts, the clamping beam is drawn towards the concrete floor andhence presses the stem feet immovable against the floor.

In another common embodiment of an equipment cabinet, the stem feet aredispensed with and instead the cabinet is secured by means of anchorbolts from the inside of the cabinet, wherein the anchor bolts extendsthrough a frame structure of the cabinet and into the concrete.Accordingly, no clamping beam is required in this embodiment.

However, when performing the securing of the cabinets to the concretefloor, in one of the ways described above, the required thickness of theconcrete is rather large. Generally a thickness of at least 160 mm ofgood quality concrete, is required for securing a cabinet in anearthquake-safe way when using four anchor bolts. Otherwise the cabinetwill be insufficiently secured. In many cases it is desired to rebuildan old plant from a conventional to an earthquake-safe plant. If thenthe concrete layer of the floor is too thin, the presently usedalternative is to remove all the equipment and cast on a new concretelayer. This involves extensive as well as expensive work, resulting in along downtime for the plant. Likewise, in many cases at newconstruction, the concrete layer must be made thicker, in order to buildearthquake-safely, than it perhaps otherwise would have been made.

When mounting the cabinets earthquake-safely, it is also necessary todrill comparatively deep holes into the concrete, which necessitates theuse of rather big and powerful equipment. Deep hole drilling alsoincreases the risk to impinge on reinforcement bars or other obstacles.

SUMMARY OF THE INVENTION

The object of the invention is to enable earthquake-safe mounting ofequipment cabinets on a concrete support structure in a simple andinexpensive way, at the same time as the necessary concrete layer may bethinner than with the prior art technique.

According to one embodiment of the invention, a securing device isprovided comprised of a comparatively thin upper assembly plate, whichmay be made of steel, and at least four spacer plates or foot plates,which also may be made of steel, which are mounted on the assembly plateand are adapted to bear against the concrete floor. The assembly plateand the spacers may present a common hole pattern, namely on one handcommon through holes for securing the securing device onto the concretefloor by means of anchor bolts, and on the other hand threaded holes forsecuring the cabinet onto the securing device. The threaded holes may bethrough holes, but need not necessarily be so since the bolts holdingthe cabinet generally, but not necessarily, end before they reach theunderlying concrete.

A device as set forth above, presents a number of advantages over theprior art. Among other things the device may present a unitary assemblywhich the cabinet interacts to secure the cabinet onto the concretefloor. Moreover, it may facilitate and allow the use of a larger numberof anchor bolts, compared to the prior art, to fasten the device, andhence also the cabinet, to the concrete floor. In the prior art it ismore difficult to increase the number of anchor bolts, since thestructure of the cabinet itself sets restrictions of where it ispossible to place the bolts. Also, bolts generally were not placed toclose to each other since this might cause cracking of the concrete.With a securing device according to the present invention, more freedomis given to place the bolts in the most optimum positions. Having alarger number of anchor bolts in the concrete causes the forces actingon the cabinet during an earthquake to be more evenly over the concretefloor, thereby making it possible to use shorter anchor bolts to holdthe same load. This in turn decreases the required concrete thickness.

Instead of a thin assembly plate having spacer plates, a thick plate maybe used. Also, the thickness may be uniform or variable. With a thickplate, however, the device becomes more expensive and more cumbersome tohandle during mounting, due to the increased weight. The choice of theplate thickness depends upon weight, cost and other considerations. Byusing a thin and variable thickness securing device as describedaccording to an embodiment of the invention, a device is achieved whichhas the required thickness and strength only in the areas where this isnecessary, i.e. in the areas where the securing device is secured to theconcrete floor and the cabinet is secured to the securing device. Thisis normally in the corners of the cabinet. However, it will beunderstood that the cabinet may be secured to the securing deviceanywhere relative to the cabinet. The securing device may provide asmooth and even upper surface which facilitates displacing of thecabinet to the correct position during mounting. The upper assemblyplate also may be configured to ensure that the mutual distances betweenthe threaded holes for securing the cabinet, are maintained as requiredso as to allow and facilitate the mounting of the cabinet.

The securing device according to an embodiment of the invention, alsofacilitates the installation of the cabinet in that the securing devicesmay be mounted in advance on the concrete floor. This represents themost time-consuming work during installation of cabinets, since itinvolves position setting for the cabinets as well as drilling into theconcrete floor. When all of the securing devices are positioned, thecabinets can quickly and easily be secured to the securing devices bysimply threading of the mounting bolts into the threaded holes in thesecuring device, with or without a clamping beam as describedhereinbefore.

It is to be understood that the invention may be modified in manydifferent ways within the scope of the claims. For example, the size andform, including thickness of the securing device may be altered as wellas the size, number and position of the spacer plates on the assemblyplate. Also the number of anchor bolts into the concrete floor may bevaried. In the detailed description of an embodiment of the invention,which is given hereinafter with reference to the accompanying drawings,an embodiment is described making use of a clamping beam for securing ofa cabinet equipped with stem feet. However, the invention is alsoapplicable in combination with a cabinet lacking any stem feet and hencehaving no need for a clamping beam to secure the cabinet. Instead themounting bolts are passed through the cabinet frame and treaded into thesecuring device.

BRIEF DESCRIPTION OF THE FIGURES

The above described features and advantages of embodiments of thepresent invention will be more fully appreciated with reference to theaccompanying description and drawings, in which:

FIG. 1 is a view from above of a securing device according to anembodiment of the invention, with the positions of spacer platesindicated with dash and dot lines;

FIG. 2 is a view from above of a spacer plate;

FIG. 3 is a cross section through the securing device according to FIG.1, secured to a concrete floor by means of anchor bolts;

FIG. 4 is a view from above according to FIG. 1, with two clampingbeams, each holding two stem feet, mounted onto the securing device;

FIG. 5 is a partly exploded cross section according FIG. 2, showing anembodiment in which a clamping beam is used to mount two stem feet ontothe securing device; and

FIG. 6 is a perspective view of a cabinet secured to a concrete floorusing a securing device according to an embodiment of the invention.

DETAILED DESCRIPTION

A securing device according to an embodiment of the invention comprisesan assembly plate 1 and, in the preferred embodiment, four spacer plates2 which are positioned in the respective corners on the bottom side ofthe assembly plate. As is evident from the drawings, the assembly plate1 may be considerably thinner than each of the spacer plates 2, althoughthis is not a requirement. According to one embodiment, the assemblyplate has a thickness in the range of 3-5 mm, preferably about 4 mm,whereas each of the spacer plates has a thickness in the range of 13-17mm, preferably about 15 mm. Moreover, the assembly plate has a length ofabout 300 mm and a width of about 600 mm. It will be appreciated,however, that the surface area is variable depending on the size of thecabinet to be secured and which ranges have been stated above, theseranges do not limit the size, form or thicknesses that may beimplemented advantageously according to embodiments of the presentinvention. For example, the plates 1 and 2 may have the same thicknessor different thicknesses and may have thicknesses inside of or outsideof the ranges set forth above.

The spacer plates 2 may be mounted to the bottom side in the corners ofthe assembly plate 1, by means of four bolts 3 each. Also, further holesmay be formed in linear relationship through the assembly plate and eachspacer plate, namely for each spacer plate two through holes 4 and twothreaded holes 5. Having two, or even more, threaded holes 5 for everyspacer plate, may be implemented, though it is not necessary, to offerdifferent mounting positions for the cabinet.

The through holes 4 may be used, as is shown in a cross section of thesecuring device and a concrete floor 6 in FIG. 3, for securing thedevice to the concrete floor using anchor bolts 7 in the through holes4, wherein the spacer plates 2 may bear against the floor. Accordingly,in the mounted state of the securing device, it may have a smooth andeven upper surface, though this is not necessary.

In FIG. 5 is shown two stem feet 8, each comprising a stem 8′ and a footportion 8″, having a larger cross sectional measure than the stem, whichare to be placed upon the upper surface of the assembly plate. The stemfeet may form part of a cabinet 12, as shown in FIG. 6, and function tosupport the cabinet on the floor structure. Alternatively, the cabinetmay be designed to be secured without the use of feet. When stem feetare present, to secure the stem feet onto the securing device, aclamping beam 9 may be used. The clamping beam 9 is comprised of threeseparate beam parts 9′, 9″, 9′″ which may be telescoping lockable andreleasable in relation to each other using locking bolts 10 to renderthe clamping beam variable in length. The beam parts 9′ and 9′″ may beidentical and form the respective ends of the beam. Each of theseendparts is formed with a fork formation in the outer end, comprisingtwo fork arms 11 and an intermediate slot in the longitudinal directionof the clamping beam.

When securing the cabinet onto the securing device, the clamping beam 9may be adjusted to correct length through telescoping and subsequentlocking by the bolts 10. With a correct adjusted length, the fork arms11, in the respective end of the clamping beam, may bear against theupper side of the foot portion 8″ and the stem is positioned in the slotbetween the fork arms. Thereafter the clamping beam may be secured tothe securing device by screwing securing bolts 13 through elongatedslots 14 in the clamping beam and into the threaded holes 5 in thesecuring device. According to this technique, the stem feet are pressedagainst the upper side of the assembly plate 1 and held firmly by theclamping beams. It is contemplated, however, that any other techniquemay be used to hold the stem feet firmly against the assembly plate.

Any cabinet foot configuration is possible. For example, as is evidentfrom FIGS. 4 and 6, the distance between the stem feet at the front sideof the cabinet, is smaller than the distance between the stem feet atthe rear side of the cabinet. Consequently, the front clamping beam hasa smaller assembled length than the rear clamping beam and alsodifferent threaded holes 5 are used for the securing bolts 12. Any otherconfiguration, including more feet, is possible.

In FIG. 6 is shown, in a perspective view, a cabinet 12 secured to aconcrete floor 6 using a securing device, according to an embodiment ofthe invention. In the figure is also shown connecting plates 15, 16,which are used to interconnect securing devices for positioning cabinetsback-to-back and side-to-side, respectively. These connecting plates 15,16 may be connected using bolts into holes 17 (shown also in FIG. 1) inthe assembly plate 1. However, any convenient fastening or securingdevice may be used other than bolts.

The material used to make the plates may be any material that hassufficient strength to secure a cabinet, device, equipment or any otherobject to a concrete floor. The material may comprise, for example, ametal such as steel or a steel alloy. However, any other material,including non-metals may be used as long as the materials havesufficient strength for the application.

While particular embodiments of the present invention have been shownand described, it will be understood that changes may be made to thoseembodiments without departing from the spirit and scope of the presentinvention. For example, which securing equipment cabinets has beendescribed, it will be understood that any equipment or object may besecured to any type of floor with a securing device as described herein.

1. A securing device for earthquake-resistant securing of an equipmentcabinet to a concrete floor, comprising: an assembly plate having firstthrough holes and securing holes; and at least one spacer plate adaptedto bear against a concrete floor and having second through holes,wherein the first and second through holes are aligned and adapted tosecuring the assembly plate and the at least one spacer plate to theconcrete floor and the securing holes are adapted to secure the cabinetto the assembly plate.
 2. The securing device according to claim 1,wherein the at least one space plate comprises four spacer plates. 3.The securing device according to claim 1, wherein the securing holes arethreaded.
 4. The Securing device according to claim 1, wherein the firstand second through holes include at least eight of the first and secondthrough holes for anchor bolts.
 5. The Securing device according toclaim 3, wherein the threaded securing holes include at least eightthreaded securing holes for securing bolts.
 6. The Securing deviceaccording to claim 1, wherein the assembly plate has a thickness ofbetween 3-5 mm.
 7. The Securing device according to claim 1, wherein thespacer plates have a thickness of between 13-17 mm.
 8. The securingdevice according to claim 1, wherein the at least one spacer plate andthe assembly plate are integral.
 9. A method for earthquake-resistantsecuring of an equipment cabinet to a concrete floor, comprising:providing an assembly plate and at least one spacer plate which togetherpresent common through holes as well as common securing holes;positioning the at least one spacer plate against the concrete floor;and securing the assembly plate and at least one spacer plate throughthe common through holes to the concrete floor, to present securingholes for an equipment cabinet.
 10. The method according to claim 9,further comprising: positioning a cabinet on the assembly plate; andsecuring the cabinet onto the assembly plate through the securing holes.11. The method according to claim 9, wherein the at least one spacerplate comprises four spacer plates.
 12. The method according to claim 9,wherein the securing holes comprise threaded holes and the cabinet issecured onto the assembly plate using threaded bolts.
 13. The methodaccording to claim 9, comprising securing the assembly plate and thespacer plates to the concrete floor using at least eight anchor boltspassed through the common through holes.
 14. The method according toclaim 6, comprising securing multiple securing devices at aninstallation plant to the concrete floor, before positioning thecabinets upon the respective securing devices.
 15. The method accordingto claim 9, wherein the assembly plate and the at least one spacer plateare integral.
 16. A securing device for securing an object to a concretefloor, comprising: an assembly plate having first through holes andsecuring holes; and at least one spacer plate adapted to bear against aconcrete floor and having second through holes, wherein the first andsecond through holes are aligned and adapted to securing the assemblyplate and the at least one spacer plate to the concrete floor and thesecuring holes are adapted to secure the object to the assembly plate.17. The securing device according to claim 16, wherein the at least onespace plate comprises four spacer plates.
 18. The securing deviceaccording to claim 16, wherein the securing holes are threaded.
 19. Thesecuring device according to claim 16, wherein the first and secondthrough holes include at least eight of the first and second throughholes for anchor bolts.
 20. The Securing device according to claim 18,wherein the threaded securing holes include at least eight threadedsecuring holes for securing bolts.